Fax machine over Fiber

A common problem/question …almost from the past.
Switching from a DSL connection (cooper pair line) to Optical Fiber (FTTH) connection a Samsung Xpress SL-M2885FW is unable to send/receive faxes.

Things that can be tried:

  • Reduce modem speed
  • Set dial mode to Tones
  • Disable ECM (error correction)
Excerpts from the M2885FW manual

• You cannot use this machine as a fax via the internet phone. For more
information ask your internet service provider.
• We recommend using traditional analog phone services (PSTN: Public
Switched Telephone Network) when connecting telephone lines to use
a fax machine. If you use other Internet services (DSL, ISDN, VolP), you can
improve the connection quality by using the Micro-filter. The Micro-filter
eliminates unnecessary noise signals and improves connection quality or
Internet quality. Since the DSL Micro-filter is not provided with the
machine, contact your Internet service provider for use on DSL Microfilter.

Other than using an online fax service is there any other solution to make it work over fiber? (Linksys PAP2T-NA…)
Have no details on how it is connected or any other devices on the network.


Hi Mark

A DSL Copper connection is based on a high frequency overlay over the original Analog POTS (Plain Old Telephony System). Probably that’s where the Printer’s FAX line was connected to.

Two years ago a long time client of mine also switched to fiber. It was not possible to get a FAX signal over the fiber (Provided by our ex monopolist, Swisscom). My client switched providers (Using the same fiber). He now gets 500 MBit/S up and down - and can use their virtual PBX, including a FAX connection…

-> Ask if your Fiber Provider has an option for FAX. Medicinal, Ingenieurs, Building and also financial companies often still need FAX…

Another solution is to have your own VoIP PBX in House, these can also handle FAX using VoIP over Fibre.

My 2 cents

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Thanks, will do as suggested.
Here there are providers, like mine, offering virtual PBX as a service.
The client’s ISP is Digi. Have to ask. They told the client (lawyers) to contact the printer supplier (which I’m not, BTW) and the manual from manufacturer says catch-22.
Nethserver’s Hylafax or an in-house server are out of the equation for the moment.

Hylafax will not work by itself with VoIP FAX…

Ask your provider to enable T38 on your FXS port. If it’s providing you the FXS service on its CPE.
Otherwise, go for a Cisco SPA112.
Or more: does Linksys PAP2T-NA support T38?



A Cisco SPA112 is also what 2 clients have from their Telcos for Fax… These do work.
Same issue… :slight_smile:

My 2 cents

Yes, the PAP2T-NA supports it but it is EOL/EOS since 2013. Just brought it in the conversation as saw it mentioned in other forums and have seen it installed on some cybercafes/parlors (phone cabins).
Your proposed solutions sounds very suitable for the case. If I do the job for the client and an ATA adapter is required maybe will use the Cisco ATA191-3PW-K9 (as a recent replacement for the former Cisco model). My providers have it in stock (as well as some Grandstream models).

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